1 files changed, 816 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/HOS/Applets/SoftwareKeyboard/SoftwareKeyboardApplet.cs b/src/Ryujinx.HLE/HOS/Applets/SoftwareKeyboard/SoftwareKeyboardApplet.cs
new file mode 100644
index 00000000..278ea56c
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Applets/SoftwareKeyboard/SoftwareKeyboardApplet.cs
@@ -0,0 +1,816 @@
+using Ryujinx.Common;
+using Ryujinx.Common.Configuration.Hid;
+using Ryujinx.Common.Logging;
+using Ryujinx.HLE.HOS.Applets.SoftwareKeyboard;
+using Ryujinx.HLE.HOS.Services.Am.AppletAE;
+using Ryujinx.HLE.HOS.Services.Hid.Types.SharedMemory.Npad;
+using Ryujinx.HLE.Ui;
+using Ryujinx.HLE.Ui.Input;
+using Ryujinx.Memory;
+using System;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace Ryujinx.HLE.HOS.Applets
+{
+    internal class SoftwareKeyboardApplet : IApplet
+    {
+        private const string DefaultInputText = "Ryujinx";
+
+        private const int StandardBufferSize    = 0x7D8;
+        private const int InteractiveBufferSize = 0x7D4;
+        private const int MaxUserWords          = 0x1388;
+        private const int MaxUiTextSize         = 100;
+
+        private const Key CycleInputModesKey = Key.F6;
+
+        private readonly Switch _device;
+
+        private SoftwareKeyboardState        _foregroundState = SoftwareKeyboardState.Uninitialized;
+        private volatile InlineKeyboardState _backgroundState = InlineKeyboardState.Uninitialized;
+
+        private bool _isBackground = false;
+
+        private AppletSession _normalSession;
+        private AppletSession _interactiveSession;
+
+        // Configuration for foreground mode.
+        private SoftwareKeyboardConfig _keyboardForegroundConfig;
+
+        // Configuration for background (inline) mode.
+        private SoftwareKeyboardInitialize   _keyboardBackgroundInitialize;
+        private SoftwareKeyboardCustomizeDic _keyboardBackgroundDic;
+        private SoftwareKeyboardDictSet      _keyboardBackgroundDictSet;
+        private SoftwareKeyboardUserWord[]   _keyboardBackgroundUserWords;
+
+        private byte[] _transferMemory;
+
+        private string         _textValue   = "";
+        private int            _cursorBegin = 0;
+        private Encoding       _encoding    = Encoding.Unicode;
+        private KeyboardResult _lastResult  = KeyboardResult.NotSet;
+
+        private IDynamicTextInputHandler _dynamicTextInputHandler = null;
+        private SoftwareKeyboardRenderer _keyboardRenderer        = null;
+        private NpadReader               _npads                   = null;
+        private bool                     _canAcceptController     = false;
+        private KeyboardInputMode        _inputMode               = KeyboardInputMode.ControllerAndKeyboard;
+
+        private object _lock = new object();
+
+        public event EventHandler AppletStateChanged;
+
+        public SoftwareKeyboardApplet(Horizon system)
+        {
+            _device = system.Device;
+        }
+
+        public ResultCode Start(AppletSession normalSession, AppletSession interactiveSession)
+        {
+            lock (_lock)
+            {
+                _normalSession      = normalSession;
+                _interactiveSession = interactiveSession;
+
+                _interactiveSession.DataAvailable += OnInteractiveData;
+
+                var launchParams   = _normalSession.Pop();
+                var keyboardConfig = _normalSession.Pop();
+
+                _isBackground = keyboardConfig.Length == Unsafe.SizeOf<SoftwareKeyboardInitialize>();
+
+                if (_isBackground)
+                {
+                    // Initialize the keyboard applet in background mode.
+
+                    _keyboardBackgroundInitialize = MemoryMarshal.Read<SoftwareKeyboardInitialize>(keyboardConfig);
+                    _backgroundState              = InlineKeyboardState.Uninitialized;
+
+                    if (_device.UiHandler == null)
+                    {
+                        Logger.Error?.Print(LogClass.ServiceAm, "GUI Handler is not set, software keyboard applet will not work properly");
+                    }
+                    else
+                    {
+                        // Create a text handler that converts keyboard strokes to strings.
+                        _dynamicTextInputHandler = _device.UiHandler.CreateDynamicTextInputHandler();
+                        _dynamicTextInputHandler.TextChangedEvent += HandleTextChangedEvent;
+                        _dynamicTextInputHandler.KeyPressedEvent  += HandleKeyPressedEvent;
+
+                        _npads = new NpadReader(_device);
+                        _npads.NpadButtonDownEvent += HandleNpadButtonDownEvent;
+                        _npads.NpadButtonUpEvent   += HandleNpadButtonUpEvent;
+
+                        _keyboardRenderer = new SoftwareKeyboardRenderer(_device.UiHandler.HostUiTheme);
+                    }
+
+                    return ResultCode.Success;
+                }
+                else
+                {
+                    // Initialize the keyboard applet in foreground mode.
+
+                    if (keyboardConfig.Length < Marshal.SizeOf<SoftwareKeyboardConfig>())
+                    {
+                        Logger.Error?.Print(LogClass.ServiceAm, $"SoftwareKeyboardConfig size mismatch. Expected {Marshal.SizeOf<SoftwareKeyboardConfig>():x}. Got {keyboardConfig.Length:x}");
+                    }
+                    else
+                    {
+                        _keyboardForegroundConfig = ReadStruct<SoftwareKeyboardConfig>(keyboardConfig);
+                    }
+
+                    if (!_normalSession.TryPop(out _transferMemory))
+                    {
+                        Logger.Error?.Print(LogClass.ServiceAm, "SwKbd Transfer Memory is null");
+                    }
+
+                    if (_keyboardForegroundConfig.UseUtf8)
+                    {
+                        _encoding = Encoding.UTF8;
+                    }
+
+                    _foregroundState = SoftwareKeyboardState.Ready;
+
+                    ExecuteForegroundKeyboard();
+
+                    return ResultCode.Success;
+                }
+            }
+        }
+
+        public ResultCode GetResult()
+        {
+            return ResultCode.Success;
+        }
+
+        private bool IsKeyboardActive()
+        {
+            return _backgroundState >= InlineKeyboardState.Appearing && _backgroundState < InlineKeyboardState.Disappearing;
+        }
+
+        private bool InputModeControllerEnabled()
+        {
+            return _inputMode == KeyboardInputMode.ControllerAndKeyboard ||
+                   _inputMode == KeyboardInputMode.ControllerOnly;
+        }
+
+        private bool InputModeTypingEnabled()
+        {
+            return _inputMode == KeyboardInputMode.ControllerAndKeyboard ||
+                   _inputMode == KeyboardInputMode.KeyboardOnly;
+        }
+
+        private void AdvanceInputMode()
+        {
+            _inputMode = (KeyboardInputMode)((int)(_inputMode + 1) % (int)KeyboardInputMode.Count);
+        }
+
+        public bool DrawTo(RenderingSurfaceInfo surfaceInfo, IVirtualMemoryManager destination, ulong position)
+        {
+            _npads?.Update();
+
+            _keyboardRenderer?.SetSurfaceInfo(surfaceInfo);
+
+            return _keyboardRenderer?.DrawTo(destination, position) ?? false;
+        }
+
+        private void ExecuteForegroundKeyboard()
+        {
+            string initialText = null;
+
+            // Initial Text is always encoded as a UTF-16 string in the work buffer (passed as transfer memory)
+            // InitialStringOffset points to the memory offset and InitialStringLength is the number of UTF-16 characters
+            if (_transferMemory != null && _keyboardForegroundConfig.InitialStringLength > 0)
+            {
+                initialText = Encoding.Unicode.GetString(_transferMemory, _keyboardForegroundConfig.InitialStringOffset,
+                    2 * _keyboardForegroundConfig.InitialStringLength);
+            }
+
+            // If the max string length is 0, we set it to a large default
+            // length.
+            if (_keyboardForegroundConfig.StringLengthMax == 0)
+            {
+                _keyboardForegroundConfig.StringLengthMax = 100;
+            }
+
+            if (_device.UiHandler == null)
+            {
+                Logger.Warning?.Print(LogClass.Application, "GUI Handler is not set. Falling back to default");
+
+                _textValue = DefaultInputText;
+                _lastResult = KeyboardResult.Accept;
+            }
+            else
+            {
+                // Call the configured GUI handler to get user's input.
+                var args = new SoftwareKeyboardUiArgs
+                {
+                    HeaderText = StripUnicodeControlCodes(_keyboardForegroundConfig.HeaderText),
+                    SubtitleText = StripUnicodeControlCodes(_keyboardForegroundConfig.SubtitleText),
+                    GuideText = StripUnicodeControlCodes(_keyboardForegroundConfig.GuideText),
+                    SubmitText = (!string.IsNullOrWhiteSpace(_keyboardForegroundConfig.SubmitText) ?
+                    _keyboardForegroundConfig.SubmitText : "OK"),
+                    StringLengthMin = _keyboardForegroundConfig.StringLengthMin,
+                    StringLengthMax = _keyboardForegroundConfig.StringLengthMax,
+                    InitialText = initialText
+                };
+
+                _lastResult = _device.UiHandler.DisplayInputDialog(args, out _textValue) ? KeyboardResult.Accept : KeyboardResult.Cancel;
+                _textValue ??= initialText ?? DefaultInputText;
+            }
+
+            // If the game requests a string with a minimum length less
+            // than our default text, repeat our default text until we meet
+            // the minimum length requirement.
+            // This should always be done before the text truncation step.
+            while (_textValue.Length < _keyboardForegroundConfig.StringLengthMin)
+            {
+                _textValue = String.Join(" ", _textValue, _textValue);
+            }
+
+            // If our default text is longer than the allowed length,
+            // we truncate it.
+            if (_textValue.Length > _keyboardForegroundConfig.StringLengthMax)
+            {
+                _textValue = _textValue.Substring(0, _keyboardForegroundConfig.StringLengthMax);
+            }
+
+            // Does the application want to validate the text itself?
+            if (_keyboardForegroundConfig.CheckText)
+            {
+                // The application needs to validate the response, so we
+                // submit it to the interactive output buffer, and poll it
+                // for validation. Once validated, the application will submit
+                // back a validation status, which is handled in OnInteractiveDataPushIn.
+                _foregroundState = SoftwareKeyboardState.ValidationPending;
+
+                PushForegroundResponse(true);
+            }
+            else
+            {
+                // If the application doesn't need to validate the response,
+                // we push the data to the non-interactive output buffer
+                // and poll it for completion.
+                _foregroundState = SoftwareKeyboardState.Complete;
+
+                PushForegroundResponse(false);
+
+                AppletStateChanged?.Invoke(this, null);
+            }
+        }
+
+        private void OnInteractiveData(object sender, EventArgs e)
+        {
+            // Obtain the validation status response.
+            var data = _interactiveSession.Pop();
+
+            if (_isBackground)
+            {
+                lock (_lock)
+                {
+                    OnBackgroundInteractiveData(data);
+                }
+            }
+            else
+            {
+                OnForegroundInteractiveData(data);
+            }
+        }
+
+        private void OnForegroundInteractiveData(byte[] data)
+        {
+            if (_foregroundState == SoftwareKeyboardState.ValidationPending)
+            {
+                // TODO(jduncantor):
+                // If application rejects our "attempt", submit another attempt,
+                // and put the applet back in PendingValidation state.
+
+                // For now we assume success, so we push the final result
+                // to the standard output buffer and carry on our merry way.
+                PushForegroundResponse(false);
+
+                AppletStateChanged?.Invoke(this, null);
+
+                _foregroundState = SoftwareKeyboardState.Complete;
+            }
+            else if (_foregroundState == SoftwareKeyboardState.Complete)
+            {
+                // If we have already completed, we push the result text
+                // back on the output buffer and poll the application.
+                PushForegroundResponse(false);
+
+                AppletStateChanged?.Invoke(this, null);
+            }
+            else
+            {
+                // We shouldn't be able to get here through standard swkbd execution.
+                throw new InvalidOperationException("Software Keyboard is in an invalid state.");
+            }
+        }
+
+        private void OnBackgroundInteractiveData(byte[] data)
+        {
+            // WARNING: Only invoke applet state changes after an explicit finalization
+            // request from the game, this is because the inline keyboard is expected to
+            // keep running in the background sending data by itself.
+
+            using (MemoryStream stream = new MemoryStream(data))
+            using (BinaryReader reader = new BinaryReader(stream))
+            {
+                var request = (InlineKeyboardRequest)reader.ReadUInt32();
+
+                long remaining;
+
+                Logger.Debug?.Print(LogClass.ServiceAm, $"Keyboard received command {request} in state {_backgroundState}");
+
+                switch (request)
+                {
+                    case InlineKeyboardRequest.UseChangedStringV2:
+                        Logger.Stub?.Print(LogClass.ServiceAm, "Inline keyboard request UseChangedStringV2");
+                        break;
+                    case InlineKeyboardRequest.UseMovedCursorV2:
+                        Logger.Stub?.Print(LogClass.ServiceAm, "Inline keyboard request UseMovedCursorV2");
+                        break;
+                    case InlineKeyboardRequest.SetUserWordInfo:
+                        // Read the user word info data.
+                        remaining = stream.Length - stream.Position;
+                        if (remaining < sizeof(int))
+                        {
+                            Logger.Warning?.Print(LogClass.ServiceAm, $"Received invalid Software Keyboard User Word Info of {remaining} bytes");
+                        }
+                        else
+                        {
+                            int wordsCount = reader.ReadInt32();
+                            int wordSize = Unsafe.SizeOf<SoftwareKeyboardUserWord>();
+                            remaining = stream.Length - stream.Position;
+
+                            if (wordsCount > MaxUserWords)
+                            {
+                                Logger.Warning?.Print(LogClass.ServiceAm, $"Received {wordsCount} User Words but the maximum is {MaxUserWords}");
+                            }
+                            else if (wordsCount * wordSize != remaining)
+                            {
+                                Logger.Warning?.Print(LogClass.ServiceAm, $"Received invalid Software Keyboard User Word Info data of {remaining} bytes for {wordsCount} words");
+                            }
+                            else
+                            {
+                                _keyboardBackgroundUserWords = new SoftwareKeyboardUserWord[wordsCount];
+
+                                for (int word = 0; word < wordsCount; word++)
+                                {
+                                    _keyboardBackgroundUserWords[word] = reader.ReadStruct<SoftwareKeyboardUserWord>();
+                                }
+                            }
+                        }
+                        _interactiveSession.Push(InlineResponses.ReleasedUserWordInfo(_backgroundState));
+                        break;
+                    case InlineKeyboardRequest.SetCustomizeDic:
+                        // Read the custom dic data.
+                        remaining = stream.Length - stream.Position;
+                        if (remaining != Unsafe.SizeOf<SoftwareKeyboardCustomizeDic>())
+                        {
+                            Logger.Warning?.Print(LogClass.ServiceAm, $"Received invalid Software Keyboard Customize Dic of {remaining} bytes");
+                        }
+                        else
+                        {
+                            _keyboardBackgroundDic = reader.ReadStruct<SoftwareKeyboardCustomizeDic>();
+                        }
+                        break;
+                    case InlineKeyboardRequest.SetCustomizedDictionaries:
+                        // Read the custom dictionaries data.
+                        remaining = stream.Length - stream.Position;
+                        if (remaining != Unsafe.SizeOf<SoftwareKeyboardDictSet>())
+                        {
+                            Logger.Warning?.Print(LogClass.ServiceAm, $"Received invalid Software Keyboard DictSet of {remaining} bytes");
+                        }
+                        else
+                        {
+                            _keyboardBackgroundDictSet = reader.ReadStruct<SoftwareKeyboardDictSet>();
+                        }
+                        break;
+                    case InlineKeyboardRequest.Calc:
+                        // The Calc request is used to communicate configuration changes and commands to the keyboard.
+                        // Fields in the Calc struct and operations are masked by the Flags field.
+
+                        // Read the Calc data.
+                        SoftwareKeyboardCalcEx newCalc;
+                        remaining = stream.Length - stream.Position;
+                        if (remaining == Marshal.SizeOf<SoftwareKeyboardCalc>())
+                        {
+                            var keyboardCalcData = reader.ReadBytes((int)remaining);
+                            var keyboardCalc     = ReadStruct<SoftwareKeyboardCalc>(keyboardCalcData);
+
+                            newCalc = keyboardCalc.ToExtended();
+                        }
+                        else if (remaining == Marshal.SizeOf<SoftwareKeyboardCalcEx>() || remaining == SoftwareKeyboardCalcEx.AlternativeSize)
+                        {
+                            var keyboardCalcData = reader.ReadBytes((int)remaining);
+
+                            newCalc = ReadStruct<SoftwareKeyboardCalcEx>(keyboardCalcData);
+                        }
+                        else
+                        {
+                            Logger.Error?.Print(LogClass.ServiceAm, $"Received invalid Software Keyboard Calc of {remaining} bytes");
+
+                            newCalc = new SoftwareKeyboardCalcEx();
+                        }
+
+                        // Process each individual operation specified in the flags.
+
+                        bool updateText = false;
+
+                        if ((newCalc.Flags & KeyboardCalcFlags.Initialize) != 0)
+                        {
+                            _interactiveSession.Push(InlineResponses.FinishedInitialize(_backgroundState));
+
+                            _backgroundState = InlineKeyboardState.Initialized;
+                        }
+
+                        if ((newCalc.Flags & KeyboardCalcFlags.SetCursorPos) != 0)
+                        {
+                            _cursorBegin = newCalc.CursorPos;
+                            updateText = true;
+
+                            Logger.Debug?.Print(LogClass.ServiceAm, $"Cursor position set to {_cursorBegin}");
+                        }
+
+                        if ((newCalc.Flags & KeyboardCalcFlags.SetInputText) != 0)
+                        {
+                            _textValue = newCalc.InputText;
+                            updateText = true;
+
+                            Logger.Debug?.Print(LogClass.ServiceAm, $"Input text set to {_textValue}");
+                        }
+
+                        if ((newCalc.Flags & KeyboardCalcFlags.SetUtf8Mode) != 0)
+                        {
+                            _encoding = newCalc.UseUtf8 ? Encoding.UTF8 : Encoding.Default;
+
+                            Logger.Debug?.Print(LogClass.ServiceAm, $"Encoding set to {_encoding}");
+                        }
+
+                        if (updateText)
+                        {
+                            _dynamicTextInputHandler.SetText(_textValue, _cursorBegin);
+                            _keyboardRenderer.UpdateTextState(_textValue, _cursorBegin, _cursorBegin, null, null);
+                        }
+
+                        if ((newCalc.Flags & KeyboardCalcFlags.MustShow) != 0)
+                        {
+                            ActivateFrontend();
+
+                            _backgroundState = InlineKeyboardState.Shown;
+
+                            PushChangedString(_textValue, (uint)_cursorBegin, _backgroundState);
+                        }
+
+                        // Send the response to the Calc
+                        _interactiveSession.Push(InlineResponses.Default(_backgroundState));
+                        break;
+                    case InlineKeyboardRequest.Finalize:
+                        // Destroy the frontend.
+                        DestroyFrontend();
+                        // The calling application wants to close the keyboard applet and will wait for a state change.
+                        _backgroundState = InlineKeyboardState.Uninitialized;
+                        AppletStateChanged?.Invoke(this, null);
+                        break;
+                    default:
+                        // We shouldn't be able to get here through standard swkbd execution.
+                        Logger.Warning?.Print(LogClass.ServiceAm, $"Invalid Software Keyboard request {request} during state {_backgroundState}");
+                        _interactiveSession.Push(InlineResponses.Default(_backgroundState));
+                        break;
+                }
+            }
+        }
+
+        private void ActivateFrontend()
+        {
+            Logger.Debug?.Print(LogClass.ServiceAm, $"Activating software keyboard frontend");
+
+            _inputMode = KeyboardInputMode.ControllerAndKeyboard;
+
+            _npads.Update(true);
+
+            NpadButton buttons = _npads.GetCurrentButtonsOfAllNpads();
+
+            // Block the input if the current accept key is pressed so the applet won't be instantly closed.
+            _canAcceptController = (buttons & NpadButton.A) == 0;
+
+            _dynamicTextInputHandler.TextProcessingEnabled = true;
+
+            _keyboardRenderer.UpdateCommandState(null, null, true);
+            _keyboardRenderer.UpdateTextState(null, null, null, null, true);
+        }
+
+        private void DeactivateFrontend()
+        {
+            Logger.Debug?.Print(LogClass.ServiceAm, $"Deactivating software keyboard frontend");
+
+            _inputMode           = KeyboardInputMode.ControllerAndKeyboard;
+            _canAcceptController = false;
+
+            _dynamicTextInputHandler.TextProcessingEnabled = false;
+            _dynamicTextInputHandler.SetText(_textValue, _cursorBegin);
+        }
+
+        private void DestroyFrontend()
+        {
+            Logger.Debug?.Print(LogClass.ServiceAm, $"Destroying software keyboard frontend");
+
+            _keyboardRenderer?.Dispose();
+            _keyboardRenderer = null;
+
+            if (_dynamicTextInputHandler != null)
+            {
+                _dynamicTextInputHandler.TextChangedEvent -= HandleTextChangedEvent;
+                _dynamicTextInputHandler.KeyPressedEvent  -= HandleKeyPressedEvent;
+                _dynamicTextInputHandler.Dispose();
+                _dynamicTextInputHandler = null;
+            }
+
+            if (_npads != null)
+            {
+                _npads.NpadButtonDownEvent -= HandleNpadButtonDownEvent;
+                _npads.NpadButtonUpEvent   -= HandleNpadButtonUpEvent;
+                _npads = null;
+            }
+        }
+
+        private bool HandleKeyPressedEvent(Key key)
+        {
+            if (key == CycleInputModesKey)
+            {
+                lock (_lock)
+                {
+                    if (IsKeyboardActive())
+                    {
+                        AdvanceInputMode();
+
+                        bool typingEnabled     = InputModeTypingEnabled();
+                        bool controllerEnabled = InputModeControllerEnabled();
+
+                        _dynamicTextInputHandler.TextProcessingEnabled = typingEnabled;
+
+                        _keyboardRenderer.UpdateTextState(null, null, null, null, typingEnabled);
+                        _keyboardRenderer.UpdateCommandState(null, null, controllerEnabled);
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        private void HandleTextChangedEvent(string text, int cursorBegin, int cursorEnd, bool overwriteMode)
+        {
+            lock (_lock)
+            {
+                // Text processing should not run with typing disabled.
+                Debug.Assert(InputModeTypingEnabled());
+
+                if (text.Length > MaxUiTextSize)
+                {
+                    // Limit the text size and change it back.
+                    text        = text.Substring(0, MaxUiTextSize);
+                    cursorBegin = Math.Min(cursorBegin, MaxUiTextSize);
+                    cursorEnd   = Math.Min(cursorEnd, MaxUiTextSize);
+
+                    _dynamicTextInputHandler.SetText(text, cursorBegin, cursorEnd);
+                }
+
+                _textValue   = text;
+                _cursorBegin = cursorBegin;
+                _keyboardRenderer.UpdateTextState(text, cursorBegin, cursorEnd, overwriteMode, null);
+
+                PushUpdatedState(text, cursorBegin, KeyboardResult.NotSet);
+            }
+        }
+
+        private void HandleNpadButtonDownEvent(int npadIndex, NpadButton button)
+        {
+            lock (_lock)
+            {
+                if (!IsKeyboardActive())
+                {
+                    return;
+                }
+
+                switch (button)
+                {
+                    case NpadButton.A:
+                        _keyboardRenderer.UpdateCommandState(_canAcceptController, null, null);
+                        break;
+                    case NpadButton.B:
+                        _keyboardRenderer.UpdateCommandState(null, _canAcceptController, null);
+                        break;
+                }
+            }
+        }
+
+        private void HandleNpadButtonUpEvent(int npadIndex, NpadButton button)
+        {
+            lock (_lock)
+            {
+                KeyboardResult result = KeyboardResult.NotSet;
+
+                switch (button)
+                {
+                    case NpadButton.A:
+                        result = KeyboardResult.Accept;
+                        _keyboardRenderer.UpdateCommandState(false, null, null);
+                        break;
+                    case NpadButton.B:
+                        result = KeyboardResult.Cancel;
+                        _keyboardRenderer.UpdateCommandState(null, false, null);
+                        break;
+                }
+
+                if (IsKeyboardActive())
+                {
+                    if (!_canAcceptController)
+                    {
+                        _canAcceptController = true;
+                    }
+                    else if (InputModeControllerEnabled())
+                    {
+                        PushUpdatedState(_textValue, _cursorBegin, result);
+                    }
+                }
+            }
+        }
+
+        private void PushUpdatedState(string text, int cursorBegin, KeyboardResult result)
+        {
+            _lastResult = result;
+            _textValue  = text;
+
+            bool cancel = result == KeyboardResult.Cancel;
+            bool accept = result == KeyboardResult.Accept;
+
+            if (!IsKeyboardActive())
+            {
+                // Keyboard is not active.
+
+                return;
+            }
+
+            if (accept == false && cancel == false)
+            {
+                Logger.Debug?.Print(LogClass.ServiceAm, $"Updating keyboard text to {text} and cursor position to {cursorBegin}");
+
+                PushChangedString(text, (uint)cursorBegin, _backgroundState);
+            }
+            else
+            {
+                // Disable the frontend.
+                DeactivateFrontend();
+
+                // The 'Complete' state indicates the Calc request has been fulfilled by the applet.
+                _backgroundState = InlineKeyboardState.Disappearing;
+
+                if (accept)
+                {
+                    Logger.Debug?.Print(LogClass.ServiceAm, $"Sending keyboard OK with text {text}");
+
+                    DecidedEnter(text, _backgroundState);
+                }
+                else if (cancel)
+                {
+                    Logger.Debug?.Print(LogClass.ServiceAm, "Sending keyboard Cancel");
+
+                    DecidedCancel(_backgroundState);
+                }
+
+                _interactiveSession.Push(InlineResponses.Default(_backgroundState));
+
+                Logger.Debug?.Print(LogClass.ServiceAm, $"Resetting state of the keyboard to {_backgroundState}");
+
+                // Set the state of the applet to 'Initialized' as it is the only known state so far
+                // that does not soft-lock the keyboard after use.
+
+                _backgroundState = InlineKeyboardState.Initialized;
+
+                _interactiveSession.Push(InlineResponses.Default(_backgroundState));
+            }
+        }
+
+        private void PushChangedString(string text, uint cursor, InlineKeyboardState state)
+        {
+            // TODO (Caian): The *V2 methods are not supported because the applications that request
+            // them do not seem to accept them. The regular methods seem to work just fine in all cases.
+
+            if (_encoding == Encoding.UTF8)
+            {
+                _interactiveSession.Push(InlineResponses.ChangedStringUtf8(text, cursor, state));
+            }
+            else
+            {
+                _interactiveSession.Push(InlineResponses.ChangedString(text, cursor, state));
+            }
+        }
+
+        private void DecidedEnter(string text, InlineKeyboardState state)
+        {
+            if (_encoding == Encoding.UTF8)
+            {
+                _interactiveSession.Push(InlineResponses.DecidedEnterUtf8(text, state));
+            }
+            else
+            {
+                _interactiveSession.Push(InlineResponses.DecidedEnter(text, state));
+            }
+        }
+
+        private void DecidedCancel(InlineKeyboardState state)
+        {
+            _interactiveSession.Push(InlineResponses.DecidedCancel(state));
+        }
+
+        private void PushForegroundResponse(bool interactive)
+        {
+            int bufferSize = interactive ? InteractiveBufferSize : StandardBufferSize;
+
+            using (MemoryStream stream = new MemoryStream(new byte[bufferSize]))
+            using (BinaryWriter writer = new BinaryWriter(stream))
+            {
+                byte[] output = _encoding.GetBytes(_textValue);
+
+                if (!interactive)
+                {
+                    // Result Code.
+                    writer.Write(_lastResult == KeyboardResult.Accept ? 0U : 1U);
+                }
+                else
+                {
+                    // In interactive mode, we write the length of the text as a long, rather than
+                    // a result code. This field is inclusive of the 64-bit size.
+                    writer.Write((long)output.Length + 8);
+                }
+
+                writer.Write(output);
+
+                if (!interactive)
+                {
+                    _normalSession.Push(stream.ToArray());
+                }
+                else
+                {
+                    _interactiveSession.Push(stream.ToArray());
+                }
+            }
+        }
+
+        /// <summary>
+        /// Removes all Unicode control code characters from the input string.
+        /// This includes CR/LF, tabs, null characters, escape characters,
+        /// and special control codes which are used for formatting by the real keyboard applet.
+        /// </summary>
+        /// <remarks>
+        /// Some games send special control codes (such as 0x13 "Device Control 3") as part of the string.
+        /// Future implementations of the emulated keyboard applet will need to handle these as well.
+        /// </remarks>
+        /// <param name="input">The input string to sanitize (may be null).</param>
+        /// <returns>The sanitized string.</returns>
+        internal static string StripUnicodeControlCodes(string input)
+        {
+            if (input is null)
+            {
+                return null;
+            }
+
+            if (input.Length == 0)
+            {
+                return string.Empty;
+            }
+
+            StringBuilder sb = new StringBuilder(capacity: input.Length);
+            foreach (char c in input)
+            {
+                if (!char.IsControl(c))
+                {
+                    sb.Append(c);
+                }
+            }
+
+            return sb.ToString();
+        }
+
+        private static T ReadStruct<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors)] T>(byte[] data)
+            where T : struct
+        {
+            GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
+
+            try
+            {
+                return Marshal.PtrToStructure<T>(handle.AddrOfPinnedObject());
+            }
+            finally
+            {
+                handle.Free();
+            }
+        }
+    }
+}